AD NUMBER: 2011-09-07

SUMMARY: This AD results from mandatory
continuing airworthiness information (MCAI) issued by an aviation
authority of another country to identify and correct an unsafe
condition on an aviation product. The MCAI describes the unsafe
condition as:

During manufacture of a number of
HP Compressor Stage 1 and 2 discs with axial dovetail slots,
anomalies at the disc post corners have been found. Fatigue crack
initiation and subsequent crack propagation at the disc post may
result in release of two blades and the disc post. This may
potentially be beyond the containment capabilities of the engine
casings. Thus, these anomalies present at the disc posts constitute
a potentially unsafe condition.

This AD has been issued to detect cracks in the high-pressure
compressor (HPC) Stage 1 and 2 disc posts, which could result in
failure of the disc post and release of HPC blades, release of
uncontained engine debris, and damage to the airplane.